232 UNIVERSITY OF COLORADO STUDIES 



ities under certain conditions. Gregariousness, though seldom accom- 

 panied by intelligence is essential to the survival of the species and 

 consequently is determined by selection. 



Flesh-eating animals are solitary. This character, though the very 

 opposite, is also determined by natural selection, because the group is 

 unfavorable to their necessary conditions of life. In the struggle for 

 existence two factors usually operate which make for gregariousness; 

 struggle for food 1 and struggle for possession of the females. 2 Those 

 males that band together in struggling for the possession of food and 

 females wall be able to drive away those that do not. Those that do 

 not band together in the struggle will be starved. Those that take 

 possession of the food and females will thrive and also be the parents 

 of the next generation of the species. Gregariousness varies around 

 an average and there will be selection away from that average according 

 to the direction in which variation is favorable. In this case since 

 gregariousness is an advantage there will be a deviation from this aver- 

 age from generation to generation in the direction of it. This law was 

 first stated by Galton, 3 and finds wide application. From generation 

 to generation the struggling groups become larger and larger and selec- 

 tion (all other things equal) favors the larger group. The development 

 of sociability in the human race and the factors responsible can be seen 

 in relation to war. War is the implement by means of which the human 

 race became socialized. The whole story of warfare is one of exploita- 

 tion by the larger and more aggressive group of the smaller. So 

 sociability is a product of natural selection in the human race after 

 consciousness had advanced far toward her. adult stage. 



Since intelligence appeared, it has been the main factor seized upon 

 by selection. But intelligence is not infrequently ignored in favor of a 

 physical character. The "Black Death" which spread all over Europe 

 and Asia during the 14th century is a good illustration of this point. 

 An account of this deadly pestilence is recorded in the Humboldt 

 Library. 4 According to this author London alone lostioo,ooo inhabitants. 

 German and other European cities sustained similar enormous losses. 



1 Darwin, Origin of Species, Natural Selection. * Hereditary Genius, p. 347. 



• Darwin, Sexual Selection. * Hecker, The Black Death. 



